some problems fixed

src/audio/Audio.cpp

@@ -63,14 +63,33 @@ bool Audio::ensureStream(){
         SDL_LogError(SDL_LOG_CATEGORY_APPLICATION, "[Audio] SDL_OpenAudioDeviceStream failed: %s", SDL_GetError());
         return false;
     }
+    // Ensure the device is running so SFX can be heard even before music starts
+    SDL_ResumeAudioStreamDevice(audioStream);
     return true;
 }
 
-void Audio::start(){ if(!ensureStream()) return; if(!playing){ current=-1; nextTrack(); SDL_ResumeAudioStreamDevice(audioStream); playing=true; } }
+void Audio::start(){
+    if(!ensureStream()) return;
+    // If no track is selected yet, try to select one now (in case tracks loaded after initial start)
+    if(current < 0) {
+        nextTrack();
+    }
+    SDL_ResumeAudioStreamDevice(audioStream);
+    playing = true;
+}
 
 void Audio::toggleMute(){ muted=!muted; }
 
-void Audio::nextTrack(){ if(tracks.empty()) return; for(size_t i=0;i<tracks.size(); ++i){ current = (current + 1) % (int)tracks.size(); if(tracks[current].ok){ tracks[current].cursor=0; return; } } current=-1; }
+void Audio::nextTrack(){
+    if(tracks.empty()) { current = -1; return; }
+    // Try every track once to find a decodable one
+    int start = current;
+    for(size_t i=0;i<tracks.size(); ++i){
+        current = (current + 1) % (int)tracks.size();
+        if(tracks[current].ok){ tracks[current].cursor=0; return; }
+    }
+    current=-1;
+}
 
 void Audio::feed(Uint32 bytesWanted, SDL_AudioStream* stream){
   if(bytesWanted==0) return;
@@ -156,7 +175,15 @@ void Audio::addTrackAsync(const std::string& path) {
 }
 
 void Audio::startBackgroundLoading() {
-    if (loadingThread.joinable()) return; // Already running
+    // If a previous loading thread exists but has finished, join it so we can start anew
+    if (loadingThread.joinable()) {
+        if (loadingComplete) {
+            loadingThread.join();
+        } else {
+            // Already running
+            return;
+        }
+    }
     loadingComplete = false;
     loadedCount = 0;
     loadingThread = std::thread(&Audio::backgroundLoadingThread, this);
@@ -174,14 +201,14 @@ void Audio::backgroundLoadingThread() {
     }
 #endif
 
-    // Copy pending tracks to avoid holding the mutex during processing
-    std::vector<std::string> tracksToProcess;
-    {
-        std::lock_guard<std::mutex> lock(pendingTracksMutex);
-        tracksToProcess = pendingTracks;
-    }
-
-    for (const std::string& path : tracksToProcess) {
+    while (true) {
+        std::string path;
+        {
+            std::lock_guard<std::mutex> lock(pendingTracksMutex);
+            if (pendingTracks.empty()) break;
+            path = std::move(pendingTracks.front());
+            pendingTracks.erase(pendingTracks.begin());
+        }
         AudioTrack t;
         t.path = path;
 #ifdef _WIN32
@@ -200,7 +227,7 @@ void Audio::backgroundLoadingThread() {
             tracks.push_back(std::move(t));
         }
         
-        loadedCount++;
+    loadedCount++;
         
         // Small delay to prevent overwhelming the system
         std::this_thread::sleep_for(std::chrono::milliseconds(10));